Symptoms of Bacterial Conjunctivitis
Bacterial conjunctivitis typically presents with purulent or mucopurulent discharge, conjunctival injection (red eye), and eyelids matted shut upon awakening, distinguishing it from the watery discharge seen in viral conjunctivitis 1.
Core Clinical Presentation
The hallmark symptoms and signs of bacterial conjunctivitis include:
Primary Symptoms
- Purulent or mucopurulent discharge - This is the most characteristic feature, appearing as thick, yellow-green discharge that persists throughout the day 1, 2
- Morning crusting - Patients report difficulty opening eyelids in the morning due to dried discharge 3
- Conjunctival injection - The "red eye" or "pink eye" appearance from bulbar conjunctival hyperemia 1
- Foreign body sensation - A gritty or irritating feeling in the eye 4
Laterality and Progression
- Can be unilateral or bilateral at presentation 1
- Often starts in one eye and may spread to the other
Distinguishing Features by Severity
Nongonococcal bacterial conjunctivitis (most common):
- Bulbar conjunctival injection
- Purulent or mucopurulent discharge
- Generally self-limited in adults 5
Gonococcal conjunctivitis (severe, requires urgent treatment):
- Marked eyelid edema
- Marked bulbar conjunctival injection
- Significant purulent discharge (hyperpurulent)
- Preauricular lymphadenopathy
- Critical warning sign: corneal infiltrate or ulcer, often beginning superiorly, which may lead to corneal perforation 1
Age-Specific Patterns
Neonates (0-28 days)
- Manifests within 1-7 days after birth (gonococcal) 1
- Eyelid edema and bulbar conjunctival injection
- Discharge may be purulent, mucopurulent, or blood-stained
- No follicles present in chlamydial cases 1
Children
- Bacterial conjunctivitis is more common than viral (71% vs 16%) 6
- Most commonly caused by Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis 4
- Associated finding: otitis media (sensitivity 0.24, specificity 0.91, positive LR 2.5) 6
Adults
- Viral conjunctivitis is actually more common than bacterial (78% vs 16%) 6
- When bacterial, most commonly caused by Staphylococcus species 3
Key Diagnostic Clues
Features that increase likelihood of bacterial (vs viral) etiology:
- Mucopurulent discharge (sensitivity 0.76, specificity 0.66, positive LR 2.1) 6
- Concomitant otitis media (positive LR 2.5) 6
- Sticky eyes on awakening 4
Features that suggest viral (NOT bacterial) etiology:
- Watery discharge
- Pharyngitis (positive LR 5.4-9.9) 6
- Preauricular lymphadenopathy (positive LR 2.5-5.6) 6
- Contact with another person with red eye (positive LR 2.5) 6
Important Clinical Pitfall
No single symptom or sign differentiates bacterial from viral conjunctivitis with high certainty 6. The diagnosis is primarily clinical based on the constellation of findings, with purulent discharge being the most reliable indicator. Cultures are unnecessary in typical cases 4.